1(>2 ECONOMIC GEOLOGY OF SILVERTON QUADRANGLE, [bull. 182. 
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the Susquehanna and Aspen claims were being worked at a profit, 
while in 1876 the Prospector lode was developed by two shafts, 100 
and 130 feet deep, connected by a drift 100 feet long. The product 
of the group up to 1880 has been estimated at over $200,000. In 1882 
the Aspen group, embracing the Aspen, Susquehanna, Mammoth, 
Legal Tender, Matchless, and McGregor claims, was one of the best 
developed properties in the district and had over 5,000 feet of work- 
ings. During this year its operators contracted to furnish Sweet & Co. , 
in Silverton, with 8,000 tons of ore, which were crushed, sampled, and 
sent to the new smelter in Durango. In 1893 the Mint reports credit 
the mine with a product of $75,000, and in 1897, $78,000. In 1892 the 
output, according to the same authority, was $50,916. In all, 11,423 
tons of ore have been produced since January 1, 1884. 
Pig. 12.— Plan and longitudinal section of the workings of the Aspen mine, Hazelton Mountain. 
As the mine has been idle for several years, it was impracticable in 
1899 to make a satisfactory study of its underground workings. In 
1900, however, some progress had been made toward opening or retim- 
bering the Amy tunnel, connecting with the 800-foot level. Access 
to a small portion of the lode was obtained through the Legal Tender 
tunnel. The vein at the point cut by the tunnel strikes N. 50° W. and 
dips southwest at about 80°. It is small at this place, accompanied 
by soft gouge and disturbed by som e cross faulting. The Legal Ten der 
tunnel shows the country rock to be traversed b}^ several other veins 
running generally parallel to the Aspen. 
The Aspen workings are in rocks belonging to the Silverton series, 
exhibiting chiefly the characteristic breccia structure already de- 
scribed and containing much rock of rhyolitic character. The lowest 
